﻿using System;

    class Program
    {
        static void Main(string[] args)
        {
            int? integer = null;
            Console.WriteLine("null value: "+integer);
            integer = 9;
            Console.WriteLine("9 value: "+integer);
            double? variable = null;
            Console.WriteLine("null value: "+variable);
            variable = 5.5;
            Console.WriteLine("5.5 value: "+variable);
        }
    }